How to change Linux I/O Scheduler during runtime

This post describes the steps on how to change the Linux I/O scheduler dynamically while running a Linux operating system. You can refer to the previous post on the explanation of the differences of Linux I/O schedulers.

I/O schedulers determine how disk read/write are managed by the Linux kernel. Changing I/O scheduler requires you to know the name of your block device. So assuming your disk drive is “sda”, you can change the I/O scheduler using this command.

sudo echo noop > /sysfs/block/sda/queue/scheduler

This will change “sda” disk scheduler to NOOP, which is suitable for SSD drive. To display the current i/o scheduler, you only need to run this command.

cat /sysfs/block/sda/queue/scheduler
anticipatory deadline cfq [noop]

Note that, you will need to run this command each time you reboot or switch on your machine. In order to make the change permanent, you need to edit /etc/sysfs.conf and add “block/sda/queue/scheduler = noop” at the end of the file.